Internal-combustion engine



Aug. 7, 1928.

2 Sheets-Sheet 1 Filed Sept. 17, 1925 Aug. 7,' 1928.

E. H. FRIEND ET AL INTERNAL COMBUSTION ENGINE Filed Sept. 17. 1925 2 Sheets-Sheet 2 Patented Aug. 7, 1928.

UNITED STATES 1,679,766 PATENT OFFICE;

EDWARD HENRY FRIEND AND ALBERTGILEAD BENTLEY, 0F HOLBORN, LONDON, ENGLAND, ASSIGNORS-TO THE FRIEND BENTLEY ELEMENTSCOMPANY LIMITED, OF MELBOURNE, AUSTRALIA, A CORPORATION OF VICTORIA, AUSTRALIA.

INTERNAL-COMBUSTION ENGINE.

Application filed September 17, 1925, Serial No. 56,874, and in Great Britain October 18, 1924.

This invention relates to Diesel and other liquid fuel injection internal combustion engines of the kind in which a fixed abutment of piston type is employed, upon which a reciprocating .6 piston ofsleeve type slides.

According to this invention the piston of sleeve type moves within a cylinder, the upper or outer end of which is partly closed by a fixed abutment of cylindrical form and of a diameter smaller than the internal diameter of the cylinder, leaving room for the sleeve portion of the piston to slide upon the abutment and withinthe fixed cylinder, the piston thus forms two combustionspaces of different capacities, one inside the sleeved portion betweenthe'piston head and the end of the fixed abutment and the other between the piston head and the lower cylinder cover. Liquid fuel is injected into each combustion space by injection valves fitted. respectively in the fixed abutment, so as to inject the liquid fuel into the space within the piston sleeve, and in the lower part of the cylinder,

so as to inject the liquid fuel into the cylinder between the piston head and the cylinder cover. A sliding fluid tight jolnt between the fixed abutment and the inner face of the piston sleeve is made b piston rings carried by the lower portion 0 the abutment and the piston head is, of course, also provided with the usual piston rings to form a fluid tight sliding joint with the fixed cylinder. The bottom cylinder cover is preferably carried by the outer wall or jacket of the cylinder and projects'into the lower end of the inner cylinder wall or liner, a gas tight joint being made by rings of piston.

ring typefitted to the inwardly projecting portion of the cylinder cover.

The piston, fixed abutment and, cylinder end or cover are liquid cooled (usually water or oil but for convenience referred to hereinafteras water cooled) and to provide for eflicient cooling-of the piston and sleeve wall the piston may 'befluted, thereby 1providing a large number of water channe s leading from the upper. end to the hollow piston head and. communicating with the internal water space of the piston through passages at the lower end of the fluting. On the outer side of the piston sleeve is'fitted a water jacket sleeve which binds tightly on the fluted wall and has a sliding fit with'the cylinder.

an engine embodying this invention, the sections being taken at right angles to one another and showing the piston at opposite ends of its stroke; and

Figures 3 and 4 are horizontal sections taken respectively on the lines .12, a; and y, y of Figure 2.

Figure 5 is a horizontal section taken on the line zz' of Figure 1 through the upper end of the sleeved piston.

A the cylinder liner. B is the piston with piston sleeve C. D is the fixed abutment. E is the bottom cylinder cover. F is the trunnion ring carrying external trunnions f to which the small ends 9 of the connecting rods G are connected. H is the lower part of the engine frame comprisin supporting legs mounted on the base 1 and carrying at the upper end the'exhaust and is the crank shaft to which the large ends g of the connecting rods G are connected .at opposite sides of the engine. The drawings show the invention as applied to a single cylinder but, it is of course equally applicable to a single cylinder or a multicylinder engine.

The fixed abutment D, which is cooled, is supported from the detachable fixed cross member M'by the tubular rods m which are made hollow for the admission and outlet of cooling liquid into and from the Water space (1 of the abutment, which may carry a central fuel injection valve d and other necessary valves. The cross member M is mounted on top of the upper frame or casing K.

It will be seen that the sleeve. C of the piston B slides between the cylinder A and the abutment D, so that one combustion space N is formed within the sleeveBbetWeen the piston and the lower end of the abutment D while the second combustion space N is 'piston B and the bottom cylinder cover ment carries piston ringsd to form a sliding joint for the piston sleeve and the piston is provided with the piston rings bto form a fluid tight sliding joint with the fixed cylinder A. The outer wall or jacket (1 of the cylinder carries the bottom cylinder cover E, which is secured in place by the ring 6 and the studs 6 a pressure tight joint being pro vided between the cover and the lower end of the cylinder liner A by the rings 6 This attachment allows the cylinder cover to be readily removed from the. bottom of the cylinder by removing the studs 6 and ring e, when the cover is free to drop; or the cover can be drawn upwards through the cylinder- It will be seen that the two working spaces N N are of different diameters, the lower space N having the inner diameter of the fixed cylinder liner A, while the upper working space N has the inner diameter of the piston sleeve C, so that the two spaces differ by the thickness of the piston sleeve, thus providing for a more powerful stroke from the lower combustion space to compensate for the extra work called for on the upward stroke in raising the moving parts.

In double acting engines of the normal type the-lower combustion space is of the same diameter as the upper combustion space, and the area of lower combustion space is reduced by the area of the usual piston rod. These features, in conjunction with the obliquity of the connecting rods result in the power transmitted from the lower combustion space to the crank shaft being substantially less than that from the upper combustion space. In this design, however, as the lower combustion space is of larger diameter than the upper, and as the area of the lower combustion space is not reduced by the introduction of a piston rod, and further as the connecting rod obliquity is reduced since the rods are much longer than in normal types of engine, it is possible, by suitably proportioning the parts, to provide for substantially equal power to be transmitted to the crank shaft from both the upper and lower combustion spaces, thus ensuring a uniform torque on the crank shaft.

The cooling water space a for the cylinder is formed partly inside the liner A and partly between the liner and the outer wall a. The water cooling of the piston is providcd for by fiuting or recessing the piston sleeve, adjacent its lower'end as at 0,1 forming a number of longitudinally arranged water channels 0' and narrow passages 0* and cov-' ering the recess at the lower end of the sleeve by a water jacket sleeve 0 which binds tightly on the piston and has a sliding fit within the cylinder. The upper ends of the channels 0 communicate by means of radially arranged holes 0 with a pair of grooves or recesses 0 formed in the periphery of the upper end of the sleeved piston, and the lower end of the recess 0 is in communication with the inside of the piston head by way of the passages 0. The cooling water is supplied a'nd withdrawn through the supply and outlet pipes f which are connected to the trunnion ring F, so that one of the pipes f .isin communication with one of the grooves 0 and the other pipe f is in communieation with the other groove.

The upper end of the piston sleeve 0 is fitted into the lower side of the trunnion cylinder A when the piston is at the outer end of its downward stroke, these cylinder ports opening, respectively, into the inlet and exhaust channels j, j of the casing or box J surrounding the middle of the cylinder. The cylinder is provided with the corresponding inlet and exhaust ports a a. situated below the ports a 0, and serving for the lower combustion space N the ports being opened when the piston approaches the end of its upper stroke. The arrangement of ports illustrated is one suitable for an ordinary two-stroke cycle in which the air inlet and exhaust are completely con-- trolled by the piston but, of course, the arrangement may be varied and controlling valves also provided if desired. Thebottom cylinder cover E is shown as provided with two valves, one a fuel spray valve e and the other an air starting valve 6, the latter valve being fitted preferably only to the cylinder cover. While cylinder and piston sleeve ports are'shown for an engine of two stroke type the usual valves may be provided for working on a four stroke cycle.-

It will be seen that the cylinder A is free to expand downwardly on expansion by heat, a small clearance being allowed inside "the outer wall or water acket formed by the lower part of the casing, thev sliding gas tight joint between the liner or cylinder and the cover Eallowing of expansion and contraction. With a construction of engine on the lines described and shown the overall height of the engine is reduced to a minimum' and ready access is obtainable, access trunnion ring F so that the interior of the cylinder is readily reached. On the other hand, the lower part of the cylinder .can be reached merely by removing the studs e and ring e and lowering the cylinder cover E out of the end of the cylinder (or the cover may be drawn upwards through the. cylinder), so that the whole engine can be easily dismantled and'an'y part reached with facility.

What we claim and desire to secure by Letters Patent of the United States is 1. In a double-acting internal combustion engine of the type'in which fuel isignited by the heat developed by the compression of a charge of air, a cylinder closed at one end, a fixed abutment of piston type artly closing the other end of the cylin er, a sleeved piston of which the sleeved portion slides over the fixed abutment, which piston forms two combustion spaces, one of which inside the sleeved portion between the piston head and the end of the fixed abutment is smaller than the other between the piston head and the closed end of the cylinder and liquid fuel injection valves for injecting fuel into each of the combustion spaces.

2. In a double-acting internal combustion engine of. the type in which the fuel is ignited by the heat developed by the compression of a charge of air, a cylinder closed atits lower end, a fixed abutment of piston type partly closing the upper end of the cylinder, a sleeved piston of which the sleeved portion slides over the fixed abutment, which piston forms two combustion spaces, the lower of which between the piston head and the lower end of the cylinder is larger than the upper combustion spaceinside the sleeved portion of the piston, a liquid fuel injection valve fitted to the fixed abutment and adapted to inject. liquid fuel into the combustion space within the piston sleeve and another liquid fuel injection valve fitted in the opposite end of the cylinder and adapted to inject liquid fuel into the combustion space between the cylinder, a sleeved piston of which the sleeved portion. slides over the fixed abutment, which piston forms two combustion spaces of'diflerent capacities, the upper of which inside the sleeved portion between the piston head and the end of the fixed abutment is of smaller diameter than the other between the piston head and the closed end of the cylinder, inlet and exhaust ports provided in the piston sleeve to serve for the upper combustion space, inletand exhaust ports in the cylinder corresponding to the said piston sleeve ports and a second set of inlet and exhaust ports in the cylinder adapted to be covered and uncovered by the piston head, and a liquid fuel injection valve fitted to the fixed abutment and adapted to inject liquid fuel into the comb tion space within the piston sleeve and another liquid fuel injection valve fitted in the opposite end of the cylinder and adapted to inject liquid fuel into the combustion space between the piston head and Y the cylinder cover.

relatively to the cylinder cover.

'ton.

5. In an. internal combustion engine a cylinder closed at its lower end, agfixed abutment of the piston type partly closing the upper end of the cylinder, a sleeved piston of which the sleeved portion slides over the fixed abutment, a trunnion 'inemher to which the sleeved portion of the piston is secured, which trunnion member is entirely above the upper end of the cylinder, connecting rods externally to the cyl- I inder and connected to the said trunnion member, and liquid cooling means for supplying the p-iston with cooling liquid through the trunnion member.

6. In an internal combustion engine, a cylinder closed at its lower end, a fixed a utment of the piston type artly closing the upper end of the cylin er, a sleeved piston of which the sleeved portion slides over the fixed abutment, a trunnion member to which the sleeved portion of the piston is secured, external connecting rods connected to said trunnion member and liquid coolingsupply and outlet pipes for piston connected to the trunnion member and communicating with channels formed in the sleeve portion of the piston, which channels communicate at their lower ends with a cooling chamber formed in the pis- EDWARD HENRY FRIEND. ALBERT 'GILEAD BENTLEY. 

